And Weatherwatch.co.nz says that although it's not completely clear if it will affect the country, previous cyclones have been deadly because of dangerous rips and large waves.

The tropical cyclone is due to form around Fiji or Tonga and, according to computer modellings, will intensify as it drifts west, possibly becoming "severe".

It's also claiming that it will "be a much bigger storm than [Cyclone] Fehi", which struck the Pacific last week.

Niwa has dubbed the cyclone Gita and says there's a "moderate" chance of the cyclone forming over Fiji in the the next three days.

It follows from their earlier tweet in which they noticed a "disturbance" occurring in the tropics, east of Vanuatu and south of Fiji.

Keeping an eye on the tropics 👀There are a couple of disturbances: one to the east of #Vanuatu and another to the south of #Fiji -- the latter is expected to drop down toward NZ over the weekend, bringing the potential for heavy rainfall 🌧️ pic.twitter.com/bb4OWOoejA— NIWA Weather (@NiwaWeather) February 7, 2018

WeatherMap.co.nz uses American models for its forecasts, and they show a direct hit to Northland and Auckland.

However, the European models (ECMWF) show it moving into the Tasman Sea and in a position that could affect either island of New Zealand.

"It's still early to know if this cyclone will directly affect us," says Weatherwatch.co.nz.

However, MetService says the weather event was still a week away and a bit too far off to be precise.

Meteorologist Kyle Lee said they were aware of the cyclone forming and had a team of forecasters keeping an eye on it.

"But as it gets closer to the time and the models are a bit more certain on what they want we will definitely be updating our forecasts and watches and warnings accordingly. At this stage it's a bit too far out for us yet to say, yes, that's definitely going to happen."

Meanwhile, Northlanders are being warned to brace for heavy rain as the MetService predicts up to 130mm of rain could fall on the region in 21 hours from 6pm.

MetService says a humid easterly flow over the northern half of the North Island will dump up to 130mm of rain in Northland, mainly about the eastern hills, from this evening until-mid afternoon tomorrow.

Some will be heavy and thundery and more heavy rain is possible about the eastern hills of Northland on Friday evening.